First, you must know that you will never be able to get the source code of a page that is not on the same domain as your page in javascript. (See http://en.wikipedia.org/wiki/Same_origin_policy).

In PHP, this is how you do it :

file_get_contents($theUrl);

In javascript, there is three ways :

Firstly, by XMLHttpRequest : http://jsfiddle.net/635YY/1/

var url=../635YY,xmlhttp;//Remember, same domain

if(XMLHttpRequest in window)xmlhttp=new XMLHttpRequest();

if(ActiveXObject in window)xmlhttp=new ActiveXObject(Msxml2.XMLHTTP);

xmlhttp.open('GET',url,true);

xmlhttp.onreadystatechange=function()

{

    if(xmlhttp.readyState==4)alert(xmlhttp.responseText);

};

xmlhttp.send(null);

Secondly, by iFrames : http://jsfiddle.net/XYjuX/1/

var url=../XYjuX;//Remember, same domain

var iframe=document.createElement(iframe);

iframe.onload=function()

{

    alert(iframe.contentWindow.document.body.innerHTML);

}

iframe.src=url;

iframe.style.display=none;

document.body.appendChild(iframe);

Thirdly, by jQuery : http://jsfiddle.net/edggD/2/

$.get('../edggD',function(data)//Remember, same domain

{

    alert(data);

});